I was switching through breakers to isolate outlets. I had the panel door open, stepped away, and when I walked back to touch the panel's DOOR, I got a static-like shock on my finger. I was wearing socks & rubbed across carpet before I touched it, so I'm wondering if this was a harmless static shock, or something faulty going on? It came straight from the door-- didn't even have a chance to touch a breaker. Left my hand a bit prickly, so I've been worried.
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28Touch it a second time - if you get zapped again, it wasn't static.– Nuclear HoagieOct 24, 2019 at 13:15
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15Shocks from home electricity feel different than a zap of static. Mains power will make your whole arm or hand buzz or jerk. You would know the difference.– JPhi1618Oct 24, 2019 at 15:28
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5@JPhi1618 Ain't that the truth...lol– JACKOct 24, 2019 at 16:04
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7AC mains will typically cause your muscles to contract, in spasms equal to mains frequency. DC tends to have a single pulse, similar to static. If you ARE going to touch a suspect circuit, use the BACK of your hand - this prevents your muscles gripping a live circuit.– Alan CampbellOct 24, 2019 at 23:50
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7I hope you weren't opening the circuit breaker panel without shoes on. Rubber soled shoes are to electrical work what pants are to going out in public.– ChrisBOct 25, 2019 at 1:18
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4 Answers
Like Captain Kirk said when he sensed a trap, "It's never a bad time for a battle-stations drill".
It's never a bad time to go through and thoroughly inspect your Grounding Electrode System to assure it's in good order. You may have gotten blindsided by something like the water company severing your water pipe ground by inserting a plastic smart meter.
answered Oct 24, 2019 at 20:13
Harper - Reinstate MonicaHarper - Reinstate Monica
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So in the plastic pipe scenario... is there some straightforward continuity check that would determine this? I guess from the metal pipe on one side of the water meter to the pipe on the other side? (Presuming it isn't obviously plastic!) Oct 25, 2019 at 12:33
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1@DaveInCaz You need physical inspection, not electrical. There's a procedure for validating it electrically but the equipment is so expensive you are better off hiring it done. Even if you were trying to wing-ding it, you'd need a megger. Oct 25, 2019 at 12:41
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1A megger on a ground then what is the reference? An earth ground impedance meter is the only way to truly know what your ground is, there are 2 types amp clamp and multi point. I am one of the few electricians in my area that has them as a clamp cost ~1200 for a certified model, the multi point are 1/2 that but you have to drag probes out and stick them in earth at different distances.– Ed BealOct 25, 2019 at 17:56
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1It is easy with the correct tool not hard at all but a megger is not the correct tool.– Ed BealOct 25, 2019 at 18:31
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1@EdBeal
It is easy with the correct tool not hard at all [...]Like my father-in-law likes to say, work is 80% having the right tools and 20% knowing what to do with them. Oct 26, 2019 at 0:42
What's that cliche "Err on the side of caution" especially if it could be a shock hazard.
From what you are describing, you could be building a static charge on your person by sliding across a carpet and discharging to a grounded object. So the static flow is from you (ungrounded) to the panel(grounded). The way you can find out is to shuffle you feet and see if you can create the situation on another piece of equipment. Use a key or butter knife and as you firmly hold it see if you can create a spark without shocking yourself.
On the other hand you might be getting a shock from the panel (ungrounded) to yourself (grounded). Even though this is highly unlikely, it means you may be dealing with a totally ungrounded electrical system. I don't know if you have the skill set to go through and safely verify if the equipment is properly grounded, but a trained electrician who is skilled and trained to inspect and make repairs may be the route you need to take.
Remember safety is the key. Do not take any chances when dealing with electrical shock.
Good luck
answered Oct 24, 2019 at 13:16
The metal case of the box is bonded to ground so it is a static discharge. If you reach and touch it again you should now be discharged and nothing will happen. We used to love it when mom bought nylon or rayon socks instead of cotton because they built up the best static, we used to charge up and sneak behind and touch the ear lobe. Lots of fun for brothers that loved to torment each other. Static charges can be tens of thousands of volts but their is almost no current. A really good one will leave the nerves buzzing for a while.
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2Like Ed implies, there's almost no conceivable circumstance where the panel isn't bonded to at least neutral, and almost certainly to ground. There should be no danger. Oct 24, 2019 at 13:56
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2"There should be no danger"...??? Check it first! Don't miss the answer from @RetiredMasterElectrician.– ChrisBOct 25, 2019 at 1:12
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1I've been zapped by a 100,000V static charge, it hurt. I saw a teacher get zapped by 300,000V through his little toe (forgot to ground before stepping off his insulator)--and he limped for the rest of the class period. Oct 25, 2019 at 3:30
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2@AlanCampbell those are special induced static, which is something you have to deliberately do... I hope the OP doesn't try to build up static and then go touch a circuit breaker panel...– NelsonOct 25, 2019 at 4:02
Did you just touch the door for a blink of an eye or were you holding it for longer time (seconds)? Was it a zap or it was your hand itching whole time you touched the door?
- You touched the door for a blink: I can't say, it may be both cases. Do investigate further with multimeter/probe.
- It was a zap: You gained a static charge and when touching grounded door you discharged. This is normal and usually harmless. If it bothers you, change clothing that causes you charging.
- It was a continuous itch: There are several issues with your circuitry:
- There is some contact of hot wire connected to your ground wire - that's why the ground wires got energized.
- The circuit is not properly grounded - that's why the circuit closes through your high-resistance body.
- The whole braker panel etc. is connected to the ground wire only - that's why it can shock you.
If I were I'd measure the AC voltage of the door against proper ground (water piping, heating,...) and see what kind of shock you got.
If it proves it's the third option you are to face shut all your brakers and turn on one at time and look for the branch, that leaks. Check all the devices connected to this branch, replace/repair/get repaired the faulty ones.
Then check all the ground wires properly connected and properly grounded - it seems there might be some loose wire connection.
If in any doubt, do not hesitate calling an electrician it. It is not a shame to call an expert. It's a shame when someone get hurt or house is burned down besause of someone's false expertise.
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Second bullet point, end of the second sentence. I think you got halfway through writing "usually not dangerous", decided to switch to "usually harmless", and accidentally left "usually not harmless"! - Too small a change to edit. Oct 25, 2019 at 9:43
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@MartinBonner thanks for the correction. I've changed a haff of the sentence when writing and left the other untouched. All resulted in the nonsense.– CrowleyOct 25, 2019 at 10:04